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Background : Adequate dose to Clinical Target Volume is needed to control tumour and to deliver adequate dose without missing the target, this Clinical Target Volume must be encompassed by two margins for uncertainties; first, Internal margin uncertainties and second, set up margin uncertainty will form Planning Target Volume. Three mm setup error of couch location resulted in 38% decrease of minimum target radiation dose and 42 % increase of minimal Spinal Cord and Parotid Gland radiation dose. Aims and Objectives : Objectives of this retrospective study are, before implementation of high precession radiotherapy technique for Head and Neck Malignancy, we want determine optimal 3-dimensional Clinical Target Volume to planning target volume margin and to assess our setup accuracy in our institute, NRS Medical College & Hospital, Kolkata. Material and Methods : We analyzed retrospectively set up error from 691 set Cone Beam CT images of 94 patients. According to Standard Guidelines Target Volume delineated and for creation Clinical Target Volume to Planning target volume margin, we have used 5-7 mm margin around Clinical Target Volume. Results : In 99% patients’ setup deviation were within 0.5 cm. The population systematic error (?) in in Super Inferior; mediolateral; and anterior posterior direction were 0.13 cm, 0.12 cm and 0.14 cm respectively. The population random error in Super Inferior; mediolateral; and anterior posterior direction were 0.021 cm, 0.022 cm and 0.173 cm respectively. Using van Herk formula Clinical Target Volume to Planning Target Volume margin in Super Inferior; mediolateral; and anterior posterior direction were 0.34, 0.47 and 0.32 cm respectively. Corresponding values with Stroom formula 0.28, 0.40 and 0.26 cm respectively. Conclusions : In our study Set up margin of 5mm all around the CTV to create PTV is found to be safe and adequete
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Objective:To investigate the feasibility of individualized primary clinical target volume (CTV) delineation in intensity-modulated radiotherapy for nasopharyngeal carcinoma (NPC).Methods:Clinical data of 87 consecutive patients newly diagnosed with lateralized NPC in Jiangsu Cancer Hospital between October 2016 and February 2018 were retrospectively analyzed. Lateralized NPC is defined as tumor invasion not exceeding the contralateral wall. According to the tumor spread, the primary CTV was optimized as follows: CTV2 only covered the medial part of the contralateral pterygopalatine fossa, whereas the contralateral foramen oval was not included; on the level of parapharyngeal space, the contralateral side of CTV only covered the posterior lateral lymph nodes, whereas the contralateral internal jugular vein was not regularly covered. Failure patterns and 5-year survival [local control rate (LCR), progression-free survival (PFS) and overall survival (OS)] were evaluated by Kaplan-Meier method. Paired t-test and rank-sum test were used to analyze the dose variation in the optimized region and adverse reactions. Results:The median follow-up time was 59.5 months. The 5-year LCR, PFS, and OS were 98.9%, 86.5% and 92.1%, respectively. There was no local recurrence in the optimized area of CTV. Dosimetric comparison results showed that the doses of parotid gland, temporal lobe, cochlea and middle ear on the contralateral side were reduced by 13.45%, 9.14%, 38.83%, and 29.36%, respectively. Four cases (4.6%) developed grade 3 hearing loss, all on the ipsilateral side. The optimized scheme significantly alleviated the hearing loss on the contralateral side compared to that on the ipsilateral side ( P<0.001). Other grade 3 late adverse reactions included cranial nerve injury, subcutaneous fibrosis in the neck and visual impairment, with 1 case each. Conclusion:Individualized primary CTV for lateralized NPC is feasible and safe, with obvious dosimetric advantages and reduced adverse reaction rate, which is worthy of clinical promotion.
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Objective:To explore the method of constructing automatic delineation model for clinical target volume (CTV) and partially organs at risk (OAR) of postoperative radiotherapy for prostate cancer based on convolutional neural network, aiming to improve the clinical work efficiency and the unity of target area delineation.Methods:Postoperative CT data of 117 prostate cancer patients manually delineated by one experienced clinician were retrospectively analyzed. A multi-class auto-delineation model was designed based on 3D UNet. Dice similarity coefficient (DSC), 95% Hausdorf distance (95%HD), and average surface distance (ASD) were used to evaluate the segmentation ability of the model. In addition, the segmentation results in the test set were evaluated by two senior physicians. And the CT data of 78 patients treated by other physicians were also collected for external validation of the model. The automatic segmentation of these 78 patients by CTV-UNet model was also evaluated by two physicians.Results:The mean DSC for tumor bed area (CTV1), pelvic lymph node drainage area (CTV2), bladder and rectum of CVT-UNet auto-segmentation model in the test set were 0.74, 0.82, 0.94 and 0.79, respectively. Both physicians' scoring results of the test set and the external validation showed more consensus on the delineation of CTV2 and OAR. However, the consensus of CTV1 delineation was less.Conclusions:The automatic delineation model based on convolutional neural network is feasible for CTV and related OAR of postoperative radiotherapy for prostate cancer. The automatic segmentation ability of tumor bed area still needs to be improved.
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Objective:To evaluate the effectiveness and feasibility of 3D ResSE-Unet-based intelligent delineation of clinical target volume (CTV) in postoperative adjuvant radiotherapy for breast cancer.Methods:A total of 974 cases of breast cancer treated in the Cancer Diagnosis and Treatment Center of the Fourth Affiliated Hospital of Guangxi Medical University from September 2018 to June 2022 were enrolled in this study, including 614 cases receiving total mastectomy and 360 cases treated with breast-conserving surgery. They were divided into a training set, a validation set, and a testing set. The training set consisted of 874 cases and was used to build a model of 3D ResSE-Unet-based intelligent CTV delineation. The validation set comprised 40 cases and was used to evaluate the feasibility and effectiveness of the clinical application of AI-based CTV design in the radiotherapy for breast cancer. The testing set was composed of 60 cases and was used to test the accuracy of intelligent CTV. The Wilcoxon rank test was used to compare the Dice similarity coefficient (DSC), 95% Hausdorff distance (HD95), and average surface distance (ASD) obtained using the intelligent delineation model.Results:The intelligent delineation model showed high precision. The CTV of cases treated with total mastectomy (CTV cw) and the CTV of cases treated with breast-conserving surgery (CTV b) had DSCs greater than 0.80 and greater than 0.88, respectively. Therefore, compared with CTV cw, CTV b had a higher DSC (0.91 ± 0.03 vs.0.83 ± 0.05, t = 7.11, P < 0.05). Both CTV cw and CTV b had lower HD 95 [(7.56 ± 3.42) mm vs.(8.77 ± 5.89) mm] and ASD [(1.85 ± 0.71) mm vs.(1.86 ± 0.83)mm], without statistically significant difference ( P > 0.05). The left/right supraclavicular and infraclavicular CTV (CTV2) had DSCs greater than 0.8. CTV2 also had low average HD95 and ASD, without statistically significant difference ( P > 0.05). Conclusions:The 3D ResSE-Unet-based intelligent CTV delineation has better consistency and feasibility in postoperative adjuvant radiotherapy for breast cancer, especially the CTVs after breast-conserving surgery.
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Objective:To determine the regional boundary of para-aortic lymph node (PAN) metastasis in cervical cancer, and to explore the clinical target volume (CTV) margin.Methods:Eight-six patients with cervical cancer metastasis to PAN below and above left renal vein (LRV) were retrospectively included in this study. The anatomical relationship of the metastatic PANs and surrounding structures were analyzed according tocontrast-enhanced computed tomography (CT) and three dimensional reconstruction images.Results:Eight-six patients had metastatic PANs belowLRV: metastatic nodes were located onthe medial side of ovarian vessels and ureters, behind the renal veins, duodenum, mesenteric vessels, in front of the anterior border of lumbar vertebra and psoas. The inferior mesenteric vein was close to the left anterior side of PANs. Where the duodenum appeared, no node was presenton the anterolateral side of the inferior vena cava (IVC).Above the LRV, 27 patients had retrocrural node involvement along the azygos and hemiazgos vein, and 25/27 cases were located below the junction level of cardia and oesophagus, and 5/27 patients had metastatic lymph nodes between IVC and the right crura of diaphragm, all below the level of coeliac trunk artery.Conclusions:CTV margin delineation of PAN below and above LRV is recommended:superiorly, the junction level of cardia and oesophagus; laterally, crura and the medial side of ovarian vessels and ureters and inferior mesenteric vein; anteriorly, the posterior side of the coeliac trunk artery and renal veins and duodenum, mesenteric vessels; posteriorly, the anterior border of lumbar vertebra and psoas.
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Objective:To evaluate the effect of reducing clinical target volume (CTV) on local control and overall survival in postoperative intensity-modulated radiotherapy (IMRT), and analyze the patterns of failure, aiming to provide clinical basis for postoperative IMRT delineation of CTV for parotid gland cancer in the era of precision radiotherapy.Methods:Clinical data of 126 patients who were pathologically diagnosed with parotid gland cancer and treated with parotidectomy as well as postoperative radiotherapy were retrospectively analyzed. All patients were divided into two groups according to the prozone of CTV. It was delineated to the anterior border of parotid gland in group A, and delineated to the anterior border of masseter in group B. Actuarial estimates of local recurrence-free survival, regional recurrence-free survival, distant metastasis-free survival and overall survival were obtained with the Kaplan-Meier method. Univariate prognostic analysis was performed by log-rank test. Multivariate prognostic analysis was conducted by Cox regression model.Results:The 5-year local recurrence-free survival (LRFS), regional recurrence-free survival (RRFS), distant metastasis-free survival (DMFS) and overall survival (OS) in groups A and B were 96.7% vs. 91.3%, 96.7% vs. 90.2%, 86.9% v s. 81.3% and 86.0% vs. 81.4%, respectively. There were no significant differences in these parameters between two groups. Of 126 patients with parotid carcinoma, 7 had local recurrence. There were 2 cases in group A which 1 recurred in-field and 1 recurred out- field. And there were 5 cases in group B which 4 recurred in-field and 1 recurred marginally. Univariate analysis showed that age was associated with LRFS. Age, N stage and pathological grading were associated with OS. Cox multivariate analysis revealed that age, N stage and pathological grading were the independent influencing factors of OS. Conclusions:Reducing the CTV would not increase the risk of local recurrence in patients with parotid gland carcinoma without tumor extravasation and negative surgical margins. There is no significant difference in survival benefit compared to those delineated to the anterior border of the masseter muscle. The delineation of CTV should be treated differently according to the risk factors.
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Objective:To determine the safety of prophylactic irradiation dose CTV 60Gy optimized to CTV 50Gy for II b region in patients with stage N 0-N 1 nasopharyngeal carcinoma (NPC) and the dose advantage and clinical value for parotid gland protection, and to understand the diagnostic value of PET-CT and diffusion-weighted imaging (DWI) for suspicious positive lymph nodes in the neck (5 mm≤maximum short diameter<10 mm). Methods:Clinical data of 157 patients with primary non-metastatic NPC (N 0-N 1) admitted to our hospital from June 2015 to March 2017 were retrospectively analyzed. 104 patients underwent II b clinical target volume optimization guided by multimodal imaging system. Survival analysis was performed by Kaplan - Meier method. Univariate/multivariate regression analysis was performed to analyze the pattern of cervical lymph node recurrence. Paired t-test was used to compare the differences in target volume and parotid gland dose parameters before and after dose optimization. Results:Sixty patients underwent single-neck optimization in stage N 1, 25 patients received double-neck optimization (only those with retropharyngeal lymph node metastasis), and 19 patients underwent double-neck optimization in stage N 0. Three patients had cervical regional recurrence, all in-field. The 5-year overall survival rate was 93.3%. The lymph node recurrence-free survival rate, local recurrence-free survival rate, distant metastasis-free survival rate and disease-free survival rate were 97.1%, 91.3%, 88.5% and 80.8%, respectively. Cervical lymph node recurrence was associated with local recurrence in the nasopharynx, regardless of retropharyngeal lymph node status. Fourteen patients had suspicious positive cervical lymph nodes in II b region, with a mean maximum short diameter of 7.1 (5~9) mm on the largest cross-sectional plane, and 11 of them were positive on PET-CT, with a mean SUV max of 2.96 (2.5~3.3). There was no significant difference in GTV after optimization ( P>0.05). D mean, D max, D 50% and V 26Gy of parotid gland were significantly lower than those of conventional plan (all P<0.01). Conclusions:It is safe to optimize CTV 60Gy to CTV 50Gy in II b region in patients with N 0-N 1 NPC, and the exposure dose to normal tissues around the parotid gland and neck is significantly reduced. For small lymph nodes that do not meet the diagnostic criteria, it needs to be individualized in combination with multimodality imaging systems, such as PET-CT and DWI.
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Accurate delineation of clinical target volume (CTV) of nasopharyngeal carcinoma is of significance to prevent local recurrence and improve the survival rate of patients. When intensity-modulated radiotherapy (IMRT) was first introduced, CTV was delineated based on two-dimensional radiotherapy experience. The local recurrence-free survival is high, but the adverse reactions induced by radiotherapy are severe and the patients’ quality of life is poor. How to reduce CTV to alleviate acute and late radiotherapy-induced adverse reactions without deteriorating therapeutic effect has currently become a research hotspot. Despite the 2010 Chinese Nasopharyngeal Carcinoma IMRT Target and Dose Design Guideline Expert Consensus and the International Guideline for the Delineation of the CTV for Nasopharyngeal Carcinoma as references, the optimal individualized and standardized delineation of CTV remains controversial. This review summarizes the progress on the delineation of CTV of primary tumour of nasopharyngeal carcinoma, aiming to provide practical reference for clinicians.
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Objective:Hybrid attention U-net (HA-U-net) neural network was designed based on U-net for automatic delineation of craniospinal clinical target volume (CTV) and the segmentation results were compared with those of U-net automatic segmentation model.Methods:The data of 110 craniospinal patients were reviewed, Among them, 80 cases were selected for the training set, 10 cases for the validation set and 20 cases for the test set. HA-U-net took U-net as the basic network architecture, double attention module was added at the input of U-net network, and attention gate module was combined in skip-connection to establish the craniospinal automatic delineation network model. The evaluation parameters included Dice similarity coefficient (DSC), Hausdorff distance (HD) and precision.Results:The DSC, HD and precision of HA-U-net network were 0.901±0.041, 2.77±0.29 mm and 0.903±0.038, respectively, which were better than those of U-net (all P<0.05). Conclusion:The results show that HA-U-net convolutional neural network can effectively improve the accuracy of automatic segmentation of craniospinal CTV, and help doctors to improve the work efficiency and the consistent delineation of CTV.
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Objective:According to 2013 updated consensus guidelines of neck node levels, the distribution characteristics of cervical lymph nodes of nasopharyngeal carcinoma (NPC) were analyzed, aiming to provide preliminary reference for the clinical target volume (CTV) delineation of level Ⅴ in NPC.Methods:A total of 1110 patients pathologically diagnosed with NPC from 2012 to 2020 were retrospectively recruited for further analysis. All patients’ MRI and contrast-enhanced CT simulation scan imageswere retrospectively reviewed, metastatic lymph nodes were mapped using the 2013 International Consensus Guidelines. Then, the correlation between Ⅴa, Ⅴb and Ⅴc metastatic lymph nodes and other lymph nodes was analyzed. An NPC case diagnosed with T 1N 0M 0 was selected as the baseline standard for the normal anatomical structure and proportion of Ⅴc area. The metastatic lymph nodes in Vc were delineated on the CT simulation scan image of sample case, and the distribution characteristics of the metastatic lymph nodes inⅤc were analyzed. Results:Among the 1110 patients, 1004(90.5%) patients had lymph node metastases. The most common area of metastatic lymph node levels were level Ⅶa (74.7%) and level Ⅱb(70.7%), and the skip metastasis of lymph nodes was rare (1.0%). The multivariate analysis showed lymph node metastasis in level Va was correlated with levels Ⅱb, Ⅲ, Ⅳa, Ⅴb, and Ⅷ region ( P=0.010, 0.001, 0.001, 0.001, 0.037). Lymph node metastasis in level Ⅴb was correlated with levels Ⅲ, Ⅳa, Ⅴa and Ⅴc region ( P=0.006, 0.001, 0.001, 0.001). Lymph node metastasis in level Ⅴc was correlated with levels Ⅳb and Ⅴb region ( P=0.008, 0.001). There were 28 cases of lymph node metastasis in levelⅤc. A total of 38 metastatic lymph nodes were counted in level Vc. Among them, 33(86.8%) lymph nodes were located in the medial of the omohyoid muscle (Ⅴc-1 region), and 5(13.2%) were located in the lateral of the omohyoid muscle (Ⅴc-2 region). Conclusions:This study reflects the principle of individualized CTV delineation, which is based on the levels of nodal spread in NPC patients. When correlation is observed among different level V, V should be delineated as the moderate risk lymphatic drainage (CTV n2). It is recommended to individualized delineate level Vc when the CTV n2 covers Vc. The Ⅴc-2 region should be delineated as CTV n2 only when there is nodal spread in the ipsilateral Ⅴc-1 region.
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We use a dense and fully connected convolutional network with good feature learning in small samples, to automatically pre-deline CTV of cervical cancer patients based on CT images and evaluate the effect. The CT data of stage IB and IIA postoperative cervical cancer with similar delineation scope were selected to be used to evaluate the pre-sketching accuracy from three aspects:sketching similarity, sketching offset and sketching volume difference. It has been proved that the 8 most representative parameters are superior to those with single network and reported internationally before. Dense V-Net can accurately predict CTV pre-delineation of cervical cancer patients, which can be used clinically after simple modification by doctors.
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Female , Humans , Automation , Machine Learning , Patients , Tomography, X-Ray Computed , Uterine Cervical Neoplasms/diagnostic imagingABSTRACT
Objective: To measure the distance of the lateral, inferior, and superior microfoci from a gross tumor in a pathological speci-men and to provide scientific evidence for margin extension to form the clinical target volume (CTV) in high-dose radiotherapy for rec-tal cancer. Methods: Twenty-eight surgical specimens were collected from patients with rectal cancer who underwent total mesorectal excision (TME) in Hunan Cancer Hospital between October 2016 and April 2017. The nearest distance of the farthest peripheral micro-foci from the gross tumor was measured. The in vivo-in vitro tumor retraction factor (R1) was calculated by measuring the ratio of the tumor's perpendicular depth based on magnetic resonance imaging and immediate surgical specimens. The retraction factor (R2) in the process of pathological specimen makeup was calculated by knot labeling. The distance of microfoci extension was calculated based on that measured in pathological specimens including corrections with R1 and R2 and record as microcarcinoma extension mea-sured in vivo,MEin vivo. Results: Among the 28 pathological specimens, lateral, inferior, and superior microfoci were found in 17 (60.7%), 3 (10.7%), and 0 cases, respectively. The mean R1 was 0.913 and mean R2 was 0.803. The farthest distance measured inferiorly was 28 mm in vivo after correction. The maximum, minimum, and mean measured lateral distances were 12.03 mm, 3.03 mm, and 7.50 mm after correction, respectively. The 95% frequency value was within 10 mm. Conclusions: The lateral microfoci extension was within 10 mm for 95% of the rectal cancer patients. The margin expansion to form the CTV was suggested to be 10 mm for a late-course boost of high-dose radiotherapy for rectal cancer.
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Objective To investigate the clinical target volume (CTV)-planned target volume (PTV) setup margins during intensity-modulated radiotherapy (IMRT) for cervical cancer patients with different body mass index (BMI),aiming to provide reference for precise individual therapy.Methods Forty patients diagnosed with cervical cancer undergoing IMRT in Cancer Hospital of Fudan University between March and September 2017 were recruited and assigned into the BMI ≤ 18.4,18.5-23.9,24.0-27.9 and ≥ 28 kg/m2 groups according to the BMI classification criteria proposed by National Health and Family Planning Commission (NHFPC) of the People's Republic of China.Assisted with the bladder volume measurement device,9 cycles of kilo-voltage cone beam computed tomography (CBCT) images were subject to online registration and imaging analysis.CTV-PTV setup margins were calculated based on the formula of MPTV =2.5∑+0.7σamong four groups.Single factor variance analysis was performed.LSD test was utilized for two-group comparison.Results Among four groups,the CTV-PTV setup margins in the x,y and z directions were (6.87 mm,6.06 mm,8.49 mm),(3.13 mm,3.02 mm,3.14 mm),(4.70 mm,4.86 mm,5.31 mm) and (7.63 mm,8.28 mm,8.54 mm),respectively (P=0.038,0.048 and 0.004).Conclusions The setup errors in the BMI ≤ 18.4 and ≥28 kg/m2 groups are significantly larger compared with those in the remaining groups Consequently,CTV-PTV setup margins should be enlarged to certain extent for patients with BMI≤ 18.4 and ≥≥28 kg/m2.
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Objective To explore the pattern of lymph node metastasis and provide guidance for the delineation of clinical target volume for patients diagnosed with hypopharyngeal squamous cell carcinoma (HSCC).Methods A total of 123 patients who were initially diagnosed with HSCC by electrolaryngoscope and computed tomography (CT) of the head and neck in Shandong Tumor Hospital between 2014 and 2017 were recruited in this study.The lymph node metastasis was evaluated based on the diagnostic criteria of CT scan.The lymphatic metastasis ratio (LMR) at each node level was calculated.Analysis of variance (ANOVA) andx2 test were used to analyze the relationship between LMR and primary tumors.Results Among 123 patients,primary tumors were originated from the pyriform sinus (PS) in 101 cases (82.1％),posterior pharyngeal wall (PPW) in 15 (12.2％) and postcricoid (PC) in 7 (5.7％),respectively.The overall LMR was calculated as 84.6％ (n=104),in detail,84.2％ for patients with primary tumors originating from PS,93.3％ for those from PPW and 71.4％ for patients from PC,respectively.For PSderived tumors,the ipsilateral neck LMR at the level Ⅰa,Ⅰb,Ⅱa,Ⅱb,Ⅲ,Ⅳ,Ⅴ,Ⅵa,Ⅵb,and Ⅶ was 0,3.0％,66.3％,42.6％,46.5％,10.9％,5.0％,2.0％,7.9％,and 11.9％,respectively,and 0,0,14.9％,5.0％,3.0％,2.0％,0,0,3.0％,and 2.0％ for the contralateral neck.For PPW tumors,the ipsilateral neck LMR at the level Ⅰa,Ⅰb,Ⅱa,Ⅱb,Ⅲ,Ⅳ,Ⅴ,Ⅵa,Ⅵb,and Ⅶ was 6.7％,6.7％,66.7％,46.7％,46.7％,20.0％,0,13.3％,33.3％,and 60.0％,respectively,and 6.7％,6.7％,33.3％,26.7％,20.0％,20.0％,0,0,13.3％,and 33.3％ for the contralateral neck.For PC tumors,the ipsilateral neck LMR at the level Ⅱa,Ⅱb,Ⅲ,Ⅳ,Ⅴ and Ⅵb was 71.4％,28.6％,14.3％,14.0％,14.0％,and 14.3％,respectively,and the LMR at the level Ⅱa was 14.3％ for the contralateral neck.No lymph node metastasis occurred in other lymph node levels.The mean levels of lymph node metastasis for the T1-T4 stage tumors were 2.4,1.9,2.2,3.3 with statistical significance (P =0.023),and 2.2,4.5 and 1.6 for patients with the tumors originated from PS,PPW and PC (P=0.000).The PPW invasion was significantly correlated with the level Ⅶ metastasis (P=0.000),and PC or esophageal invasion was intimately correlated with the level Ⅵ metastasis (P=0.002 and 0.001).Conclusions The most common lymphatic metastasis includes ipsilateral neck Ⅱa,Ⅲ,and Ⅱb,whereas the level Ⅰ and Ⅴ are rarely observed.For PPW-derived tumors,the LMR at the level Ⅶ is up to 60.0％.The incidence of PC or esophageal invasion enhances the risk of level Ⅵ lymph node metastasis.
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The delineation of clinical target volume(CTV)is a critical step in planning three-dimensional conformal radiation therapy(3D-CRT)or intensity-modulated radiation therapy(IMRT)for gastric cancer.Recommendations for target volume construction have been published for two-dimensional(2D)techniques,but are scarce for 3D CT-based CTV contouring.Recent advances and controversies in delineation of postoperative radiotherapy CTV for gastric cancer have been introduced.Further optimization of target volume for postoperative 3D-CRT/IMRT in gastric cancer is necessary.
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Objective To determine the anatomic distribution of metastatic inguinal nodes in gynecological malignancies,and to explore the delineation of clinical target volume(CTV). Methods A retrospective study was performed among 34 patients with gynecological malignancies and inguinal lymph node metastases. According to the anatomic distribution of metastatic inguinal nodes, CTV covering more than 95% of inguinal lymph nodes and the relationship of inguinal nodes with the femoral vein, greater saphenous vein and its branches, superficial fascia, and deep fascia were analyzed using vascular enhancement images obtained by computed tomography and magnetic resonance imaging as well as 3D reconstruction using the Eclipse Planning System. Results The 34 patients had a total of 145 positive inguinal nodes. In the 131 superficial nodes below the inguinal ligament, 129 were located between the superficial fascia and the deep fascia;the upper group of superficial nodes,containing 25 nodes,was located at 1 cm above the public symphysis and along superficial iliac circumflex vein;the middle group,containing 85 superficial nodes and 11 patients with single superficial node metastasis,was located at the same level of the public symphysis and close to the junction of the saphenous vein and the femoral vein;the lower group, containing 21 superficial nodes,was beneath the public symphysis and along the greater saphenous vein and medial and lateral superficial femoral veins.The 14 deep nodes were located on the medial side of the femoral vein. There were no positive nodes on the posterolateral side of the link between the posterolateral edge of the femoral vein and medial edge of the sartorius muscle. The upper edge of CTV kept 142 lymph nodes beneath the upper edge of the superior pubis ramus and left 3 lymph nodes up to the upper edge of the femoral head. The lower edge of CTV kept 143 lymph nodes above the lower edge of the lesser trochanter and left 2 lymph nodes at 2 cm beneath the lower edge of the lesser trochanter. Conclusions For CTV covering 98% of positive inguinal nodes, the anterior edge is the superficial fascia;the medial edge is composed by the inguinal ligament and the border of medial muscle to the femoral vessels;the posterolateral edge is the link between the posterolateral edge of the femoral vein and the medial edge of the sartorius muscle;the upper edge is the upper border of the femoral head;the lower edge is the lower border of the lesser trochanter.
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The delineation of clinical target volume (CTV) is a critical step in planning conformal radiotherapy for rectal cancer.Several guidelines suggest different subvolumes and anatomical boundaries in radiotherapy for rectal cancer, potentially leading to a misunderstanding of CTV definition.This article reviews recent advances in the delineation of CTV in radiotherapy for rectal cancer.
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Objective To better understand the relationship between the maximum tumor diameter and the most distant micrometastases in different types of non-small cell lung cancer (NSCLC) and to provide histological evidence for the delineation of clinical target volume (CTV) from gross tumor volume.Methods We retrospectively studied the pathological specimens from 113 surgically treated NSCLC patients (44 squamous cell carcinoma patients and 69 adenocarcinoma patients) who were admitted to our hospital from 2014 to 2015.The maximum tumor diameter was determined by a combination of gross and microscopic measurements.Micrometastases were microscopically determined.The distances between the tumor edges and micrometastases outside the tumor boundaries were measured by an ocular micrometer followed by a calculation.Quantitative data were analyzed by t test, and qualitative data were analyzed by logistic regression.Results The regression relationship between the maximum tumor diameter and micrometastases was significant in the adenocarcinoma group, but not significant in the squamous cell carcinoma group (P=0.151).The association between the presence or absence of lymph node metastasis and the most distant micrometastasis was significant in the adenocarcinoma group, but not significant in the squamous cell carcinoma group (P=0.597).No association between the degree of tumor differentiation and the most distant micrometastasis was observed in either group (P=0.113).The average measurement of the most distant micrometastases was 2.94 mm in the adenocarcinoma group, with 7.5 mm as the distance to cover 95% of the most distant micrometastases.To reach the same coverage, 4 mm was needed for tumor size smaller than 3 cm, 6 mm for those between 3 cm and 5 cm, and 7.5 mm for those larger than 5 cm.The average measurement of the most distant micrometastases was 2.69 mm in the squamous cell carcinoma group, with 6 mm as the distance to cover 95% of the most distant micrometastases.Conclusions For NSCLC, the most distant micrometastasis of adenocarcinoma is associated with the maximum tumor diameter and presence or absence of lymph node metastasis, and the CTV should thus be adjusted accordingly;no relevance between the most distant micrometastasis and maximum tumor diameter is observed in squamous cell carcinoma;there is no relationship between the most distant micrometastasis and the degree of tumor differentiation in adenocarcinoma and squamous cell carcinoma.
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Objective To preliminarily explore the delineation of clinical target volume in intensity-modulated radiotherapy for para-aortic lymph node metastases in patients with gynecological malignancies.Methods A retrospective analysis was performed on 56 gynecological tumor patients with para-aortic lymph node metastases who were admitted to our department from January 2010 to September 2016.The number and distribution of metastatic para-aortic lymph nodes were determined by imaging method.Results A total of 108 positive para-aortic lymph nodes were found in the 56 patients,with 1-4(mean,2) positive para-aortic lymph nodes per patient.The mean diameter of positive para-aortic lymph nodes was 2.3 cm (1.2-4.0 cm).A total of 20 metastatic lymph nodes (19%) were located at the L4 level,38(35%) at the L3 level,44(41%) at the L2 level,and 6(5%) at the L1 level.There were 71 metastatic lymph nodes (66%) at the left side of the para-aortic region,20 metastatic lymph nodes (19%) between the abdominal aorta and the vena cava,and 17 metastatic lymph nodes (15%) at the right side of the inferior vena cava.Conclusions For patients with gynecological malignancies,nodal contouring for the para-aortic region should not be defined by a fixed circumferential margin around the vessels.The left side of the para-aortic region should be covered adequately;the upper target should be extended up to the renal artery,and needs to be further extended for patients who have nodal involvement near the renal arteries and veins.
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Chemoradiotherapy is a major treatment for inoperable esophageal carcinoma (EC).However, there is still controversy over the target volume for radiation, particularly nodal target volume.EC is characterized by a high rate of lymph node metastasis, and its metastatic pattern is not always predictable.Elective nodal irradiation (ENI) will increase the radiation field, which may increase the incidence of adverse events.Some investigators used involved-field irradiation (IFI) to reduce treatment-related toxicities without compromising survival.Studies have demonstrated that regional and distant micrometastases can be controlled, to some extent, by chemotherapy, incidental irradiation, and the abscopal effects of radiation.With either ENI or IFI, EC recurrence is usually found in the primary tumor and at distant sites, without survival difference.These data suggest that IFI is feasible in EC patients.